4047721 has 2 divisors, whose sum is σ = 4047722. Its totient is φ = 4047720.

The previous prime is 4047709. The next prime is 4047737. The reversal of 4047721 is 1277404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4044121 + 3600 = 2011^2 + 60^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4047721 is a prime.

It is equal to p₂₈₆₃₄₂ and since 4047721 and 286342 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (4047761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2023860 + 2023861.

It is an arithmetic number, because the mean of its divisors is an integer number (2023861).

Almost surely, 2^4047721 is an apocalyptic number.

It is an amenable number.

4047721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4047721 is an equidigital number, since it uses as much as digits as its factorization.

4047721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1568, while the sum is 25.

The square root of 4047721 is about 2011.8948779695. The cubic root of 4047721 is about 159.3688810159.

The spelling of 4047721 in words is "four million, forty-seven thousand, seven hundred twenty-one".